The image is from a new article by “David Law”:http://dss.ucsd.edu/~dslaw/Welcome.html and “Mila Versteeg”:http://www.law.uchicago.edu/faculty/versteeg in the _California Law Review_ (non-gated version “here”:http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1643628). They estimated how “statist” or “libertarian” constitutions are from new data that codes what rights constitutions do and do not explicitly protect. They then estimate country “ideal points” using W-NOMINATE; the same “method political scientists use”:http://www.voteview.com/ to estimate how liberal or conservative Congressmen are. The authors summarize their conclusions as follows:
bq. We find empirically that the world’s constitutions can be arrayed along a single ideological dimension. At one end of the spectrum, some constitutions can be characterized as relatively libertarian, in the sense that they epitomize a common law constitutional tradition of negative liberty and, more specifically, judicial protection from detention or bodily harm at the hands of the state. At the other end of the spectrum, by contrast, some constitutions are more statist in character: they both presuppose and enshrine a far-reaching role for the state in a variety of domains by imbuing the state with a broad range of both powers and responsibilities.
The paper has a lot more detail and graphs. The most interesting substantive conclusion is that there is evidence of polarization in the ideological underpinnings of constitutions:
bq. We show that the world’s constitutions are increasingly dividing themselves into two distinct families-one libertarian in
character, the other statist. Within each family, constitutions are becoming increasingly similar to one another, but the families themselves are becoming increasingly distinct from one another. The dynamics of constitutional evolution, in other words, involve a combination of ideological convergence and ideological polarization.